Dual fuel burner apparatus

ABSTRACT

A dual fuel burner apparatus for burning two or more different types of fuel some of which require greater amounts of primary air entrapped with the fuel than others and comprising a first nozzle for a first fuel having an orifice directed into and located adjacent to the entrance end of a mixer chamber of the customary type leading toward a customary burner, a second nozzle for a second fuel having an orifice also directed into and located adjacent to the entrance end and adjacent to the first nozzle with the first fuel requiring more primary air for proper burning than the second fuel, a shutter at the second nozzle orifice partially blocking primary air to the second fuel but having an open portion adjacent the first nozzle orifice providing relatively freer flow of primary air to the first fuel than to the second fuel.

United States Patent [191 Qualley et al. [45] Aug. 13, 1974 DUAL FUEL BURNER APPARATUS Primary Examiner-Carroll B. Dority, Jr. 75 Inventors; Ray w Quauey; Robert L. Attorney, Agent, or Firm-Hofgren, Wegner, Allen,

Thompson, both of Racine, Wis. Stenma" & Mccord [73] Assignee: klodine Manufacturing Company, [57 acme A dual fuel burner apparatus for burning two or more [22] Filed: Aug. 20, 1973 different types of fuel some of which require greater amounts of primary air'entrapped with the fuel than [211 App]' 389888 others and comprising a first nozzle for a first fuel having an orifice directed into and located adjacent to the [52] U.S. Cl. 431/354, 48/180 C' e trance end of a mixer chamber of the customary [51] Int. Cl. F23d 13/40 type ead ng toward a' ry b e a econ [58] Field of Search 431/354, 355, 156; nozzle for a second fuel having an orifice also directed 48/180 C, 180 P, 1803, 180 R into and located adjacent to the entrance end and ad- '1 jacent to the first nozzle with the first fuel requiring [56] References Cited more primary air for proper burning than the second UNITED STATES PATENTS fuel, a shutter at the second nozzle orifice partially l 175 888 3/1916 d 48]]80 blocking primary air to the second fuel but having an I?! 982 mm M 2; 1::1'1::::::::::::::::::::::'i31,354 eeee eeeiee eeieeem the feet eeeele eefiee eeeeeiee relatively freer flow of primary air to thefirst fu to the second fuel.

5 Claims, 3 Drawing Figures BURNER el than PAIENIEn mm 31974 BURNER DUAL FUEL BURNER APPARATUS SUMMARY OF THE INVENTION One of the features of this invention is to provide an improved dual fuel burner apparatus in which two fuel nozzles are located adjacent to each other and directed toward and into the entrance end of a fuel and air mixer chamber in combination with a shutter partially blocking primary air flow to the second nozzle but having an open portion providing substantially free flow of primary air to the first fuel as it is emitted from the first fuel nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified side elevational view of a mixer, burner and fuel supply for selectively providing one of two different fuels to the mixer in the burner.

FIG. 2 is an enlarged fragmentary side elevational view of the apparatus of FIG. 1.

FIG. 3 is an elevational view of the fuel supply of the apparatus of this embodiment as viewed substantially from line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment illustrated in the drawings of the invention there is provided a customary burner for the usual plurality of jets of flame as illustrated at 11 with the burner being supplied with a fuel and air mixture from a mixer 12 communicating therewith. This mixer 12 is provided with an entrance end 13 of bell shape of the customary type in which fuel and air are mixed before passing on to the burner 10. This mixture is then ejected from the burner in the customary manner and produces the flames indicated schematically at 11 in FIG. 1.

In order to burn efficiently different types of fuels such as natural gas and a different gas of which propane is the usual example it is necessary to provide different ratios of primary air to the different types of fuel. Thus, in general, a gas such as propane tends to draw in or aspirate too much primary air for optimum burning. The burner apparatus of this invention provides an automatic device for supplying the proper amount of primary air when the burner operation is switched from natural gas to propane or butane gas and back again by a simple fixed shutter device that although adjustable in postion does not require movement after the position has been determined and the shutter device locked in this position.

In the embodiment illustrated in the drawings the mixer-burner is supplied with a first fuel from a manifold l4 and this first fuel may be, for example, natural gas. There is also provided an adjustable manifold 15 for a second fuel which may be a gas such as propane. The first manifold 14 is provided with a plurality of first nozzles 16 of which only one is shown and each of these first fuel nozzles 16 has an orifice 17 adjacent the entrance end 13 of the chamber 12 with this first orifice l7 directing fuel and entrained primary air into the mixer and thus into the burner 10.

The second manifold 15 is also provided with a plurality of second nozzles 18 of which again only one is shown and it likewise has an orifice 19 located adjacent the entrance end 13 and angled to direct the mixed fuel and primary air into the mixer 12 and thus into the burner 10. The second fuel supplied by the maniold 15 and nozzles 18 is of the type that tends to draw in too much primary air if freely exposed in the manner of the natural gas nozzles 16. As mentioned, a good example of this second fuel is a fuel such as propane. Each of the manifolds l4 and 15 is supplied by its respective fuel pipes 20 and 21.

In order to provide automatic control of the amount of primary air aspirated by the various fuels there is located a shutter 22 at and slightly behind the exit from the second nozzle orifice 19 so as to partially block primary air drawn into the emitted second fuel for mixing with the fuel in the mixing chamber 12. Thus in the illustrated embodiment the shutter 22 is in the form of an annular plate that is located just rearwardly of the exit end 23 of each second nozzle 18. When'the second fuel is emitted through the orifice 19 under the customary high pressure it would ordinarily draw into it the primary air from the atmosphere. However, because of the positioning of the shutter 22 free flow of this primary air is partially blocked so that only the required small amount of primary air is drawn into the exiting fuel.

The shutter 22 has an open portion 24 as seen most clearly in FIG. 3 adjacent to the first nozzle 17 orifice end 25 that provides relatively freer flow of primary air to the fuel exiting from the first nozzle orifice 17. For better control of the primary air supplies to each of the nozzles 16 and 18 the shutter 22 is provided with spaced rearwardly extending flanges 25 that are at substantially right angles to the planar shutter 22 and that extend rearwardly of the shutter and away from the chamber entrance end 13. These flanges 25 are spaced from and located on opposite sides of the first nozzles 16 so as not to interfere substantially with the flow of primary air into the fuel streams emitted from the first nozzle orifices 17.

The shutter 22 may be adjustably positioned longitudinally of the second nozzle 18 so as to determine more precisely the amount of primary air supplied to the fuel from the second nozzles 18. In the illustrated embodiment this adjustment is provided by a surrounding cylindrical collar 26 that is slidable on the exterior of each nozzle 18 and that is locked in position by a set screw 27. Once in the locked position which will be determined by the nature of the fuel supplied by the second manifold 15 the shutter will automatically control the amount of primary air that is permitted to the second fuel without substantial interference with the primary air to the first fuel emitted by the nozzle 16.

The importance of this invention is that it provides a simple shutter device for controlling the amount of primary air where two or more fuels are supplied selectively to a single burner apparatus and with these fuels requiring different amounts of primary air for proper burning. Thus it is frequently necessary to switch from one fuel to another whenever one of the fuels is in short supply. Thus when the principal fuel is natural gas it is often necessary to switch to a gas such as propane or butane and these fuels require different flow orifices and amounts of primary air because of their different burning characteristics. This invention provides for this automatically because in the sets of nozzles 16 and 18 that receive fuel from different manifolds such as those illustrated at 14 and 15 the internaldimensions of the nozzles can be determined and the adjustable shutter 22 provides the proper amount of primary air. Thus when the system is operated on natural gas where the entire gas supply will be by way of the manifold 14 and nozzles 16 extending therefrom the burner apparatus will function in its normal manner and when a different type of gas is supplied as through the manifold the different nozzles and the shutters will provide the ideal burning conditions'for this alternate fuel.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the appended claims.

We claim:

1. A dual fuel burner apparatus, comprising: a mixer chamber means for fuel and primary air having an entrance end; a first nozzle for a first fuel having an orifice directed into and located adjacent to said entrance end; a second nozzle for a second fuel having an orifice directed into and also located adjacent to said entrance end and adjacent to the first nozzle, said second fuel tending to aspirate more primary air for optimum burning than said first fuel; and a shutter about said second nozzle orifice partially blocking primary air to said second fuel and having an open portion adjacent said first nozzle orifice through which said first nozzle directs fuel and providing relatively freer flow of primary air to said first fuel than to said second fuel.

2. The burner apparatus of claim 1 wherein said shutter comprises an annular member extending around said second nozzle orifice adjacent the exit thereof and being annularly continuous except for an open portion at said orifice of the first nozzle through which said first fuel and its primary air are directed.

3. The burner apparatus of claim 2 wherein said shutter is provided with spaced flanges extending away from the shutter and said chamber at said opening, the flanges being located on opposite sides of said first nozzle orifice.

4. The burner apparatus of claim 2 wherein means are provided for adjustably positioning said shutter longitudinally of said second nozzle orifice.

5. The burner apparatus of claim 2 wherein said shutter is provided with spaced flanges extending away from the shutter and said chamber at said opening, the flanges being located on opposite sides of said first nozzle orifice, and means are provided for adjustably positioning said shutter longitudinally of said second nozzle 

1. A dual fuel burner apparatus, comprising: a mixer chamber means for fuel and primary air having an entrance end; a first nozzle for a first fuel having an orifice directed into and located adjacent to said entrance end; a second nozzle for a second fuel having an orifice directed into and also located adjacent to said entrance end and adjacent to the first nozzle, said second fuel tending to aspirate more primary air for optimum burning than said first fuel; and a shutter about said second nozzle orifice partially blocking primary air to said second fuel and having an open portion adjacent said first nozzle orifice through which said first nozzle directs fuel and providing relatively freer flow of primary air to said first fuel than to said second fuel.
 2. The burner apparatus of claim 1 wherein said shutter comprises an annular member extending around said second nozzle orifice adjacent the exit thereof and being annularly continuous except for an open portion at said orifice of the first nozzle through which said first fuel and its primary air are directed.
 3. The burner apparatus of claim 2 wherein said shutter is provided with spaced flanges extending away from the shutter and said chamber at said opening, the flanges being located on opposite sides of said first nozzle orifice.
 4. The burner apparatus of claim 2 wherein means are provided for adjustably positioning said shutter longitudinally of said second nozzle orifice.
 5. The burner apparatus of claim 2 wherein said shutter is provided with spaced flanges extending away from the shutter and said chamber at said opening, the flanges being located on opposite sides of said first nozzle orifice, and means are provided for adjustably positioning said shutter longitudinally of said second nozzle orifice. 